Flexible micro-LED display panel and manufacturing method thereof

Abstract

The present application provides a flexible micro-LED display panel and a manufacturing method thereof. The flexible micro-LED display panel includes a first base substrate, a thin film transistor array layer, a first connecting electrode layer, a second connecting electrode layer, a plurality of micro-LED chips, a flexible encapsulation layer, and a second base substrate, wherein the first base substrate and the second base substrate are flexible substrates, the second base substrate is provided on the flexible encapsulation layer covering the micro-LED chips to make a neutral layer of the panel to be located at the thin film transistor array layer, reducing a risk of wiring disconnection.

What is claimed is: 
     
       1. A flexible micro-LED display panel, comprising:
 an array substrate, comprising a first base substrate and a thin film transistor array layer disposed on the first base substrate; 
 a first connecting electrode layer, disposed on the thin film transistor array layer and electrically connected to the thin film transistor array layer; 
 a second connecting electrode layer, disposed on the first connecting electrode layer; 
 a plurality of micro-LED chips, arranged on the second connecting electrode layer, and connected to the thin film transistor array layer via the first connecting electrode layer and the second connecting electrode layer, wherein a first pin and a second pin are provided on a side of each of the micro-LED chips close to the second connecting electrode layer, and the first pin and the second pin are connected to the second connecting electrode layer to achieve die bonding; 
 a flexible encapsulation layer, covering the micro-LED chips; and 
 a second base substrate, disposed on the flexible encapsulation layer and being directly in contact with the flexible encapsulation layer, 
 wherein the first base substrate and the second base substrate are both flexible substrates, the flexible display panel has a neutral layer located at the thin film transistor array layer, and the neutral layer is an imaginary horizontal line at which a stress received by the flexible micro-LED display panel during folding and bending is zero; and 
 wherein the first base substrate and the second base substrate are respectively located on two opposite sides of a combined structure of the micro-LED chips and the flexible encapsulation layer. 
 
     
     
       2. The flexible micro-LED display panel according to  claim 1 , wherein the first base substrate and the second base substrate are made of CPI. 
     
     
       3. The flexible micro-LED display panel according to  claim 1 , wherein the array substrate further comprises:
 a barrier layer, disposed on the first base substrate; 
 a light-shielding layer, disposed on the barrier layer; 
 a buffer layer, covering the light-shielding layer and the barrier layer; 
 an active layer, disposed on the buffer layer, wherein the light-shielding layer and the active layer are arranged opposite to each other; 
 a gate insulating layer, disposed on the active layer; 
 a gate layer, disposed on the gate insulating layer; 
 an interlayer dielectric layer, covering the gate layer, the active layer, and the buffer layer; 
 a source and a drain, disposed on the interlayer dielectric layer and connected to the active layer; 
 a passivation layer, covering the source, the drain, and the interlayer dielectric layer, wherein the first connecting electrode is disposed on the passivation layer; and 
 a black matrix layer, disposed between adjacent ones of the micro-LED chips, wherein the flexible encapsulation layer covers the micro-LED chips, the black matrix layer, and the second connecting electrode. 
 
     
     
       4. The flexible micro-LED display panel according to  claim 3 , wherein the light-shielding layer, the gate layer, the source, and the drain are made of aluminum-neodymium alloy. 
     
     
       5. The flexible micro-LED display panel according to  claim 3 , wherein the active layer is made of IGZO. 
     
     
       6. The flexible micro-LED display panel according to  claim 1 , wherein a thickness of the second base substrate ranges from 8 μm to 12 μm. 
     
     
       7. A flexible micro-LED display panel, comprising:
 an array substrate, comprising a first base substrate and a thin film transistor array layer disposed on the first base substrate; 
 a first connecting electrode layer, disposed on the thin film transistor array layer and electrically connected to the thin film transistor array layer; 
 a second connecting electrode layer, disposed on the first connecting electrode layer; 
 a plurality of micro-LED chips, arranged on the second connecting electrode layer, and connected to the thin film transistor array layer via the first connecting electrode layer and the second connecting electrode layer; 
 a flexible encapsulation layer, covering the micro-LED chips; and 
 a second base substrate, disposed on the flexible encapsulation layer and being directly in contact with the flexible encapsulation layer, 
 wherein the first base substrate and the second base substrate are both flexible substrates, the flexible display panel has a neutral layer located at the thin film transistor array layer, and the neutral layer is an imaginary horizontal line at which a stress received by the flexible micro-LED display panel during folding and bending is zero; and 
 wherein the first base substrate and the second base substrate are respectively located on two opposite sides of a combined structure of the micro-LED chips and the flexible encapsulation layer. 
 
     
     
       8. The flexible micro-LED display panel according to  claim 7 , wherein the first base substrate and the second base substrate are made of CPI. 
     
     
       9. The flexible micro-LED display panel according to  claim 7 , wherein the array substrate further comprises:
 a barrier layer, disposed on the first base substrate; 
 a light-shielding layer, disposed on the barrier layer; 
 a buffer layer, covering the light-shielding layer and the barrier layer; 
 an active layer, disposed on the buffer layer, wherein the light-shielding layer and the active layer are arranged opposite to each other; 
 a gate insulating layer, disposed on the active layer; 
 a gate layer, disposed on the gate insulating layer; 
 an interlayer dielectric layer, covering the gate layer, the active layer, and the buffer layer; 
 a source and a drain, disposed on the interlayer dielectric layer and connected to the active layer; 
 a passivation layer, covering the source, the drain, and the interlayer dielectric layer, wherein the first connecting electrode is disposed on the passivation layer; and 
 a black matrix layer, disposed between adjacent ones of the micro-LED chips, wherein the flexible encapsulation layer covers the micro-LED chips, the black matrix layer, and the second connecting electrode. 
 
     
     
       10. The flexible micro-LED display panel according to  claim 9 , wherein the light-shielding layer, the gate layer, the source, and the drain are made of aluminum-neodymium alloy. 
     
     
       11. The flexible micro-LED display panel according to  claim 9 , wherein the active layer is made of IGZO. 
     
     
       12. The flexible micro-LED display panel according to  claim 7 , wherein a thickness of the second base substrate ranges from 8 μm to 12 μm. 
     
     
       13. A method of manufacturing a flexible micro-LED display panel, comprising following steps:
 preparing an array substrate, wherein the array substrate comprises a first base substrate and a thin film transistor array layer formed on the first base substrate; 
 sequentially forming a first connecting electrode layer, a second connecting electrode layer, and a black matrix layer on the thin film transistor array layer, wherein the first connecting electrode layer and the second connecting electrode layer are electrically connected to each other; 
 transferring a plurality of micro-LED chips to the second connecting electrode layer, and performing a die bonding process so that the micro-LED chips are connected to the thin film transistor array layer through the first connecting electrode layer and the second connecting electrode layer; 
 forming a flexible encapsulation layer on the micro-LED chips; and 
 forming a second base substrate directly on the flexible encapsulation layer, so that the flexible display panel has a neutral layer located at the thin film transistor array layer, wherein the neutral layer is an imaginary horizontal line at which a stress received by the flexible micro-LED display panel during folding and bending is zero; and 
 wherein the first base substrate and the second base substrate are both flexible substrates; and 
 wherein the first base substrate and the second base substrate are respectively located on two opposite sides of a combined structure of the micro-LED chips and the flexible encapsulation layer. 
 
     
     
       14. The method of manufacturing the flexible micro-LED display panel according to  claim 13 , wherein preparing the array substrate comprises:
 providing the first base substrate, and sequentially forming a barrier layer, a light-shielding layer, and a buffer layer on the first base substrate; and 
 forming the thin film transistor array layer on the buffer layer, the thin film transistor array layer comprising an active layer, a gate insulating layer, a gate layer, an interlayer dielectric layer, a source, a drain, and a passivation layer sequentially formed on the buffer layer. 
 
     
     
       15. The method of manufacturing the flexible micro-LED display panel according to  claim 13 , wherein the first base substrate and the second base substrate are made of CPI. 
     
     
       16. The method of manufacturing the flexible micro-LED display panel according to  claim 13 , wherein the light-shielding layer, the gate layer, the source, and the drain are made of aluminum-neodymium alloy. 
     
     
       17. The method of manufacturing the flexible micro-LED display panel according to  claim 13 , wherein a thickness of the second base substrate ranges from 8 μm to 12 μm.